Test patterns are sometimes included in a video signal for calibrating or troubleshooting the downstream signal path. The test patterns are typically generated by test signal generators, and they allow vendors, viewers and television stations to adjust their equipment for desired functionality. By way of example, such test patterns may include an eight vertical color bar pattern, as well as the slightly more complex Society of Motion Picture and Television Engineers (SMPTE) color bar pattern. Such patterns may also be used to indicate that there is a problem or error with the signal feed, or they may be used to indicate the beginning or end of a signal feed.
Accordingly, when processing broadcast video data it may often be desired to detect the presence of such test patterns to ensure the accuracy of a received video data. However, this task has traditionally been performed manually, which can be cumbersome and relatively time consuming for video editors.
Various approaches have been developed for automatically determining video signal attributes for different purposes. For example, U.S. Pat. No. 4,951,128 discloses a method for detecting correlation of a video signal having a chrominance component by combining three successive line intervals of the video signal to produce a first signal by obtaining the sum of the video signals of those three line intervals, combining at least two of those three line intervals to produce a second signal by obtaining the difference between the video signals of such two line intervals. The method further includes detecting the absolute values of the first and second signals, respectively, and determining the difference between the absolute values of the first and second signals to produce a correlation indication signal.
Despite the existence of such approaches, further developments may be desirable to provide automated pattern recognition of test or other patterns in video data.